Stranded materials, upon manufacture, are typically taken up directly onto a reel or spool. Utility reels and spools are well known in the art and are widely used for containing and dispensing wire, tubing, fabric and other stranded products which lend themselves to being wound helically and/or over themselves. The reel or spool is generally comprised of a cylindrical tube or barrel having at its ends two flanges, each having an inside and an outside face, the axis of the barrel extending normally from the faces defined by the inside surface of each flange.
A take-up reel or spool receives a strand directly from the last step in the manufacturing process. Thereafter, the filled reel is effective for storage and handling purposes. Upon sale or distribution, the spool is often placed on an arbor, either alone or with other spools, for convenient dispensing of the linear or stranded material. Linear or stranded materials include electrical wire whether in single or multiple strands and cable (comprised of multiple wires), rope, wire rope, hose, tubing, chain and plastic and rubber profile material (generally any polymeric or elastomeric, extruded flexible material). In general, a host of elongate materials as diverse as pharmaceutical unit dose packages, fiberoptic line and log chains are stored on reels. Likewise, ribbon, thread and other stranded materials are wrapped on spools.
The requirement for a reel or spool in the manufacture and handling of wire is substantially different than spools in the textile industry. For example, the weight of wire is several times the weight of thread or rope. The bulk of wire, which translates to the inverse of density, is substantially lower for wire than for hose, tubing or even chain.
Meanwhile, many spools or reels are typically launched on a one way trip. The collection and recycling of spools is hardly worth the effort in many instances, considering that their materials are not easily recyclable. In the art, a typical spool has a tubular or "barrel" portion extending between two flange portions positioned at either end.
Spools may be assembled, adding costly operations in manufacturing. Moreover, spools may break at the corner where the tube portion meets the flange portion or may fracture at an engagement portion along the tube portion. Three-piece spools typically break near the corner between the flange and the tube portion or where a joint bonds the tube portion to the flange portion.
What is needed is plastic spools that may be easily made, using automated processes minimizing human intervention, that are strong enough to tolerate the abuse of use when fully wrapped with wire or cable, and which may be easily recycled, such as by re-grinding for shipping.
Large spools are typically called reels in the wire industry. Heavy-duty reels of 12 inches in diameter and greater (6 feet and 8 feet are common) are often made of wood or metal. Plastic spools of 12-inch diameter and greater are rare and tend to be very complex. The rationale is simple. Inexpensive plastics are not sufficiently strong to tolerate even ordinary use with such a large mass of wire or cable wrapped around the spool.
Moreover, large flanges for reels are very difficult to manufacture. Likewise, the additional manufacturing cost of large spools is problematic. Designs do not always scale up. Assembly adds to cost, but costs of destroying conventional, multi-material (e.g wood/steel, plastic/steel/paperboard, or sheet metal) reels for sorting and re-grinding materials can be exorbitant.
A large reel or spool is usually manufactured of wood. Nevertheless, a plastic spool in 12-inch diameter may also be manufactured with a pair of plastic flanges holding a layered cardboard (paperboard) tube retained therebetween. The flanges are typically bolted together axially to hold the tube within or without a circumferential detent as with wooden reels.
Such reels have an additional difficulty during use. The flanges do not stay secured. One difficulty with the structural integrity of such a "three-piece," bolted, reel design is that the tube or barrel is not actually fastened to the flange. The flange and tube are often precarious assemblies held together by three or more axial bolts compressing the flanges together. The tube is prone to slip with respect to the flanges, breaking, tilting or otherwise losing its integrity under excessive loads. Such loads result from the impact of dropping onto a floor from a bench height or less (alternatively, a standard drop test). For the largest reels, rolling over or into obstacles or from decks during handling is likely a cause of reel or cable damage.
In the vernacular of the wire manufacturing and supply industry, "spools" have flange diameters up to 10 inches; "reels" have flange diameters greater than 10 inches. Hereinafter, however, the term "reel" shall be understood to apply to either a spool or a reel.
Generally, each flange has a round, central, arbor hole extending into the tube or barrel. An arbor inserted through the central arbor hole in one flange, through the hollow barrel and through the central arbor hole in the other flange provides an axle on which the reel may rotate. A drive hole (dog aperture) is also generally provided in the outside surface of one or both flanges a short distance from the arbor hole to accommodate an externally engaging dog or drive pin (dog, pawl) which orbits the arbor axis and causes the reel to rotate, winding the product onto the barrel.
Instead of a drive hole separate from the arbor hole, a spool may have a non-circular, mating shape for cooperatively engaging a rotating arbor having a corresponding cross section. The product to be stored on the reel is usually attached to the reel and is drawn onto the barrel in a winding fashion as the reel is rotated.
In the case of wire products, at least one of the flanges usually has a pair of through holes for receiving the wire. The first of the pair is a start hole and is located outwardly adjacent the outer surface of the barrel. The second of the pair is a finish hole located near the flange periphery. The leading end of a wire is fed through the start hole from inside of the flange and is knotted, bent or otherwise engages the flange such that the wire will be tensioned by rotation of the reel about the arbor axis. The wire is then cut and the trailing end of the reeled wire is fed through the finish hole and knotted or bent such as to prevent the wire from unraveling from the reel.
Previous utility reels have been assembled from sheet metal, wood, paperboard, or plastic components. Assembly of sheet metal reels may require inserting tabs extending axially from the tube through receiving slots in the flanges and bending or staking the tabs to retain the flanges to the barrel.
Plastic polymeric reels, component barrels, and flanges may be made of ABS, polystyrene, and other materials bonded, welded, or fastened together. Polymers, metal, wood, and other materials are subject to a significant risk of breakage in the field. In very cold environments, plastics become brittle. Because they do not become unacceptably brittle under cold conditions, polyolefin materials such as polyethylene or poylpropylene materials have been used. These materials, however, are chemically inert and are not bonded or reliably welded. Therefore, assembly of polyolefin reel components usually requires interlocking tabs and slots. Regardless of the type of plastic used, manufacturing a plastic reel thus involves two or more distinct steps at workstations remote in time and space. Molding the components occurs at a molding machine. Assembly requires another operation elsewhere.
As a means of storing and dispensing wound, stranded products, a reel itself provides no value to an end user once emptied of product. A great need exists to reduce the cost of providing such products without reducing quality. An economical, durable reel to meet the requirements of product manufacturers and end user is needed.